Fuzzy logic/neural network adaptive critic controller design

A neural net (NN)/fuzzy logic (FL) adaptive critic controller is described. This structure takes advantage of the decision-making properties of a FL system to critique and tune a NN action-generating network. The stability of the proposed structure is proven. NN and fuzzy weight tuning algorithms are given that do not require complicated initialization procedures or any off-line learning phase. Tracking and bounded NN weights and control signals are guaranteed. The adaptive fuzzy critic controller given here is a "model-free controller" in the sense that it works for any system in a prescribed class without the need for extensive modeling and preliminary analysis to find a "regression matrix". There is no linearity in the parameter (LIP) requirement.